Device and method for controlling injection of liquid embolic composition

ABSTRACT

A liquid embolic delivery system is provided for trapping an injected liquid embolic composition to prevent the liquid embolic from solidifying or otherwise passing outside of an embolization area. The delivery system includes a catheter for delivery of a liquid embolic composition and a containment member positioned at a distal end of the catheter which is shaped to trap the liquid embolic composition delivered through the lumen of the catheter. The containment member is formed as a brush, nest, sponge, swab, flexible sack, or other shape into and around which the liquid embolic composition is injected. The liquid embolic composition is trapped or meshes with the containment member during solidification containing the liquid embolic and preventing the embolic composition from passing into the blood stream.

This application is a continuation-in-part of U.S. Ser. No. 08/953,149filed Oct. 17, 1997, which is incorporated herein by reference in itsentirety.

BACKGROUND OF THE INVENTION

1. Field Of The Invention

The invention relates to a device for controlling injection of a liquidembolic composition into a patient, and more particularly, to a devicefor containment and restraint of a liquid embolic composition during andafter solidification. The device for controlling injection may beincorporated in a catheter system used for delivery of the emboliccomposition in a controlled manner.

2. State Of The Art

In many clinical situations it is desirable to selectively occlude bloodvessels for a variety of purposes, such as, the control or prevention ofbleeding, the prevention of blood supply to tumors, treatment ofarterial venous malformations (AVMs), and the blocking of blood flowwithin an aneurysm. Embolization of blood vessels has been performed byemploying certain polymer compositions, particulates, and/or selerosingmaterial including silicone balloons, metallic coils, PVA particles,gelatin, and the like, to selectively block blood flow in the bloodvessels. However, these embolization procedures have certain drawbacks.

Intracranial aneurysms are abnormal blood filled dilations of a bloodvessel wall which may rupture causing significant bleeding and damage tosurrounding brain tissue or death. Traditionally, intracranial aneurysmshave been surgically clipped to reduce the risk of rupture by placing ametal clip around the neck of the aneurysm to cut off and preventfurther blood flow to the aneurysm. However, many aneurysms cannot betreated surgically because of either the location and configuration ofthe aneurysm or because the condition of the patient does not permitcranial surgery.

When aneurysms cannot be treated surgically or when surgery isconsidered to be too risky or invasive, aneurysms may be treatedendovascularly with coils. The coils are placed in the aneurysm byextending a catheter endovascularly to the site of the aneurysm andpassing single or often multiple metallic coils such as platinum,stainless steel, or tungsten coils through the catheter into theaneurysm. The coils placed within the aneurysm create a thrombus whichoccludes the aneurysm and prevents further blood flow to the aneurysm.The treatment of intracranial aneurysms with coils isolates the aneurysmfrom arterial circulation, helping to guard against rupture and furthergrowth of the aneurysm. However, the use of metallic coils to treatintracranial aneurysms may not be a permanent solution because the bloodclot around the coils may lyse or dissolve due to the dynamic nature ofthe blood clotting function. Once a clot formed around the coils in ananeurysm lyses, the coil can no longer perform its function of occludingthe aneurysm. In addition, the coils may become dislodged, move from theaneurysm, and enter the patient's blood stream causing blockages atother locations within the vascular system. Coils can also form a loopextending into the blood stream which generates undesirable embolismsdownstream.

Another drawback associated with the use of coils to occlude an aneurysmis that the coils are known to compact over time leaving cavities forsubsequent aneurysm growth. In addition, if a subsequent surgicalclipping procedure is warranted, it can be difficult to place the clipover the coil mass.

Other procedures for treating aneurysms include occluding the aneurysmwith a silicone balloon or filling the aneurysm with particulatematerial.

Aneurysms having large necks are not easily treated by either surgicalclipping or by coils because the aneurysm neck may have a shape whichcannot be completely clipped surgically and the coils may tend to becomedislodged from the aneurysm when the neck is particularly large.

One minimally invasive procedure for treating intracranial aneurysmswhich addresses the problems with the surgical clipping and coiltechniques involves the endovascular injection of a liquid emboliccomposition which solidifies in the aneurysm to occlude the aneurysm.Typically, liquid embolic compositions include a water insoluble,biocompatible, non-biodegradable polymer, dissolved in a biocompatiblesolvent. Once the liquid embolic composition is injected into theaneurysm, the biocompatible solvent dissipates into the blood and thepolymer solidifies to occlude the blood flow through the aneurysm. Theseliquid embolic compositions preferably include a radiopaque materialwhich allows the physician to view the embolization procedure byfluoroscopy.

Prior to delivery of the liquid embolic composition to the aneurysm, theaneurysm and delivery device are preferably positioned so that theliquid embolic composition will be delivered by gravity into theaneurysm and will solidify and remain in the aneurysm. This means thatthe patient position is often manipulated. to position the aneurysm withthe aneurysm neck pointing up. As the embolic composition is deliveredto the aneurysm, the solvent dissipates from the polymer material and isremoved in the blood stream causing the polymer material within theaneurysm to solidify.

Depending on the rate at which the liquid embolic material is injectedinto the blood vessel and the amount of blood flow present, the polymermay remain in liquid form for a period of time while the solventdissipates into the blood stream. In addition, the solvent concentrationat the point of injection may increase to a point where small strings ofunsolidified polymer material may separate from the polymer mass and becarried away in the blood stream where the polymer can occlude anundesired vascular location.

Accordingly, it would be desirable to provide a device or method forcontrolling the solidification of the polymer material during injectionso that an aneurysm which is in a non-gravity dependent position can befilled without causing the liquid embolic composition to pass out of theaneurysm into the blood stream. It would also be desirable to preventpolymer strings from being carried away in the blood stream.

SUMMARY OF THE INVENTION

The present invention relates to a containment member for trapping aninjected liquid embolic composition to prevent the liquid embolic fromsolidifying outside of an embolization area.

In accordance with one aspect of the present invention, a liquid embolicdelivery system includes a catheter having a lumen for delivery of aliquid embolic composition to a cavity, a containment member positionedat a distal end of the catheter, and a detachment mechanism forcompletely detaching the containment member from the catheter aftersolidification of the liquid embolic composition,to allow separation ofthe catheter from a mass of solidified embolic composition. Thecontainment member is shaped to trap the liquid embolic compositiondelivered through the lumen of the catheter.

In accordance with an additional aspect of the present invention, amethod of containing a liquid embolic composition at an embolizationsite within a body includes the steps of delivering a liquid emboliccomposition to an embolization site within a body with a catheter,containing the liquid embolic composition during solidification with acontainment member, and detaching the containment member from thecatheter after solidification of the liquid embolic composition torelease the catheter from a mass of solidified embolic composition.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will now be described in greater detail with reference tothe preferred embodiments illustrated in the accompanying drawings, inwhich like elements bear like reference numerals, and wherein:

FIG. 1 is a side cross sectional view of a first embodiment of a liquidembolic delivery system with a multifilament brush in a retractedposition;

FIG. 2 is a side cross sectional view of the delivery system of FIG. 1with the multifilament brush in the extended position;

FIG. 3 is a side cross sectional view of a delivery system according toa second embodiment prior to formation of a nest;

FIG. 4 is a side cross sectional view of the delivery system of FIG. 3with a nest formed;

FIG. 5 is a side cross sectional view of a delivery system according toa third embodiment with a sponge in a retracted position;

FIG. 6 is a side cross sectional view of the delivery system of FIG. 5with the sponge in the extended position;

FIG. 7 is a side cross sectional view of a delivery system according toa fourth embodiment with a swab in a retracted position;

FIG. 8 is a side cross sectional view of the delivery system of FIG. 7with the swab in the extended position;

FIG. 9 is a side cross sectional view of a delivery system according toa fifth embodiment with a magnetic member in a retracted position;

FIG. 10 is a side cross sectional view of the delivery system of FIG. 9with the magnetic member in the extended position;

FIG. 11 is a side cross sectional view of an aneurysm being treated bythe delivery system of FIGS. 3 and 4;

FIG. 12 is a side cross sectional view of an aneurysm with a mass ofliquid embolic material filling the aneurysm;

FIG. 13 is a side cross sectional view of an aneurysm after the deliverysystem has been detached from the mass of liquid embolic material;

FIG. 14 is a side cross sectional view of a delivery system according toa sixth embodiment including a flexible sack in a retracted position;

FIG. 15 is a side cross sectional view of the delivery system of FIG. 14with the flexible sack in the extended position;

FIG. 16 is a side cross sectional view of the delivery system of FIG. 14in which liquid embolic composition has solidified within the flexiblesack;

FIG. 17 is a side cross sectional view of an aneurysm with an aneurysmneck flow disruption system;

FIG. 18 is a side cross sectional view of an aneurysm with analternative embodiment of an aneurysm neck flow disruption system;

FIG. 19 is a cross sectional view taken along line A-A of FIG. 18; and

FIG. 20 is a cross sectional view taken along line B-B of FIG. 18.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The liquid embolic delivery system includes a catheter having a lumenthrough which liquid embolic composition is delivered to an embolizationsite within the body. A containment member, such a nidus or a flexiblesack is positioned at the distal end of the catheter and, the liquidembolic composition is injected into the containment member. The liquidembolic composition is trapped or meshes with the containment memberduring solidification containing the liquid embolic and preventing theliquid embolic composition from passing into the blood stream. Thepreferred embodiments of the containment member for use with thedelivery system will be discussed below with respect to the variousfigures.

Prior to discussing the present invention in further detail, thefollowing terms are defined:

The term “liquid embolic composition” refers to a fluid composition thatis injected at an embolization site and solidifies to fully or partiallyocclude the embolization site.

The term “embolizing” or “embolization” refers to a process wherein afluid composition is injected into a blood vessel or tissue which, inthe case of, for example, aneurysms fills or plugs the aneurysm sackand/or encourages clot formation so that blood flow into the aneurysmand pressure in the aneurysm ceases, and in the case of arterial venousmalformations (AVMs) and arterial venous fistula (AVFs) forms a plug orclot to control/reroute blood flow to permit proper tissue perfusion.Embolization may be used for preventing or controlling bleeding due tolesions (e.g., organ bleeding, gastrointestinal bleeding, vascularbleeding, as well as bleeding associated with an aneurysm). In addition,embolization can be used to ablate diseased tissue (e.g., tumors, etc.)by cutting off the blood supply.

The liquid embolic composition for use in the present invention may beany biocompatible composition which solidifies within the body, forexample a biocompatible polymer combined with a suitable biocompatiblesolvent such as ethanol, dimethylsulfoxide (DMSO), ethyl lactate,acetone, and the like. Examples of embolizing compositions are describedin U.S. Pat. No. 5,667,767, which issued Sep. 16, 1997. U.S. Pat. No.5,580,568, which issued Dec. 3, 1996, and U.S. patent application Ser.No. 08/688,050 each of which are incorporated herein by reference intheir entirety.

According to one preferred embodiment of the invention in which thesolvent used is DMSO, the delivery system elements which may come intocontact with the solvent are DMSO compatible. Examples of DMSOcompatible catheter materials include polyolefins, such as polyethyleneor polypropylene; fluoropolymers, such as PTFE and ETFE, and silicones.

The liquid embolic delivery system as shown in FIGS. 1 and 2 includes anelongated flexible catheter 10 and a containment brush 12 disposedwithin the catheter. The catheter 10 may be an over the wire catheter, aflow directed catheter, or any other type of catheter capable ofdelivering the liquid embolic composition to the embolization site. Thebrush 12 includes an elongated flexible shaft 14 which extends throughthe lumen of the catheter 10 for manipulation of the brush from theproximal end of the catheter which extends outside the patient's body.The brush 12 includes a plurality of filaments 16 extendingsubstantially radially from a distal end of the shaft 14.

In use, the catheter 10 is delivered to an embolization site with thebrush 12 in the retracted position, shown in FIG. 1, in which the brushis positioned fully or substantially within the lumen. The shaft 14 isthen moved distally within the catheter 10 to extend the brush 12 fromthe distal end of the catheter. The brush 12 is positioned such that theliquid embolic composition exiting the lumen of the catheter 10 willbecome trapped by the brush. Preferably, the brush is positioned about 0to 5 mm, more preferably about 1 to 4 mm from the distal end of thecatheter with the exact position depending on the particularembolization site and procedure being performed.

Once the brush 12 has been positioned the liquid embolic composition isthen injected through the catheter 10 either through the same lumen inwhich the shaft 14 of the brush 12 extends or through a second parallellumen of the catheter. As the liquid embolic composition is delivereddown the catheter the liquid which exits the distal end of the catheteris injected into the filaments 16 of the brush 12. The solvent begins todissipate from the liquid embolic composition and the polymer materialprecipitates and meshes with the bristles of the brush. Subsequentinjections of liquid embolic material increase the mass of solidifiedembolic material surrounding the brush at the embolization site.Injection of the liquid embolic composition continues until theembolization site is completely embolized. The brush 12 acts to containand trap the precipitating material and prevent the effects of gravityand blood flow from causing the polymer material to be carried away fromthe embolization site.

After the liquid embolic composition has been delivered through thecatheter 10 and has formed a solid mass around the brush 12, the mass isdetached from the catheter and the brush shaft 14 by a detachmentmechanism, such as a mechanical, electrical, or chemical detachmentsystem as discussed below.

Although the brush 12 has been described as attached to an elongatedflexible shaft 14 which extends through the lumen of the catheter 10,the brush may also be connected by a mounting member, such as a shortshaft, directly to the distal end of the catheter. When the brush 12 isconnected directly to the end of the catheter 10 the catheter and brushmay be introduced together as a single unit through a separateintroducing catheter of a larger diameter than the catheter 10. Afterdelivery of liquid embolic composition the brush 12 may be detached fromthe catheter 10 or the entire distal end of the catheter may bedetachable.

The filaments 16 of the brush 12 are preferably flexible members formedof a material such as nylon, polyethylene, polypropylene, polyester,PTFE, Dacron, and the like. The filaments are preferably soft, flexible,absorbent, bio-compatible, and DMSO compatible. The filament size mayvary depending on the application, however, one example of a suitablefilament has a diameter of about 75 to about 500 microns, preferablyabout 150 to about 250 microns, and a length depending on an innerdiameter of the vascular site of about 1 to about 30 mm, preferablyabout 2 to about 10 mm.

FIGS. 3 and 4 illustrate an alternative embodiment of the liquid embolicdelivery system in which a wire 20 is delivered through the lumen of acatheter 22 when the wire 20 exits the distal end of the catheter 22 thewire forms into a nest configuration at the embolization site. The wire20 is preformed with a curvature which creates the nest 24 when the wireis delivered out of the distal end of the catheter 22. The shape of thenest 24 generally conforms to the shape of the embolization site, forexample, when treating an aneurysm the nest 24 will conform to the shapeof the aneurysm. The liquid embolic composition is subsequentlydelivered through the catheter lumen and is trapped by and precipitateson the wire nest 24. As in the embodiment described above, afterembolization is complete, the solidified mass of embolic material andthe wire nest 24 are detached from the catheter.

The wire 20 may be preformed to cause the nest 24 to take on aparticular predetermined shape. Examples of nest shapes include therandomly curving wire shape shown in FIG. 4 and a coil or spiral shape.The wire 20 may be formed of a biocompatible material, such as,stainless steel, platinum, Nitinol, gold, tungsten, and the like. Inaddition, it may be desirable to form the wire 20 from a shape memorymaterial, such as Nitinol.

Another alternative embodiment of the invention including a sponge likemember 30 and a catheter 32 is illustrated in FIGS. 5 and 6. As shown inFIG. 5, the sponge 30 is compressed within the lumen of the catheter 32during delivery of the catheter to the embolization site. Once thedistal tip of the catheter 32 is located at or near the embolizationsite, the sponge 30 is deployed from the catheter by a plunger or rod 34which extends through the catheter lumen 32 and connects to the sponge30. Once the sponge 30 has been deployed from the catheter 32 the spongeexpands to the configuration shown in FIG. 6. The expanded sponge 30includes a plurality of large holes 36 and smaller pores into which theliquid embolic composition is injected.

As in the embodiment of FIGS. 1 and 2, the sponge 30 of FIGS. 5 and 6may be fixed to the end of the catheter 32 instead of to the plunger 34and the entire catheter and sponge system may be delivered to theembolization site through an introducing catheter. The liquid emboliccomposition may then be delivered by the catheter 32 to an exterior oran interior of the sponge. Once an embolic mass has formed around thesponge 30 by injection of the liquid embolic composition through thecatheter lumen, the embolic mass is detached from the catheter 32 andremains within the embolization site after the catheter has beenremoved. The detachment of the solidified embolic mass from the catheter32 and the rod 34 is performed by mechanical, electrical, or chemicaldetachment as will be described further below.

The sponge member 30 according to the embodiment of FIGS. 5 and 6 isformed of a biocompatible, open cell, compressible material having ahigh porosity, such as polyethylene sponge, polypropylene sponge,polyurethane sponge, PVA, fluoropolymer, and the like. The size andshape of the sponge 30 will be modified to properly fit within theparticular embolization site. The sponge material is preferably abiocompatible, DMSO compatible, non-toxic, soft, hydrophillic materialwhich fully fills the aneurysm. An expansion ratio of the sponge ispreferably about 5:1 to 20:1, more preferably about 10:1.

FIGS. 7 and 8 relate to a further alternative embodiment of theinvention in which the containment member for trapping the liquidembolic composition is a swab shaped member 40 of a filamentousmaterial. The swab shaped member 40 may be compressed within anddeployed from the lumen of a catheter 42 by a pusher or rod 44 or can bepermanently affixed to the distal end of the catheter and insertedthrough an introducing catheter. The liquid embolic composition which isdelivered through the catheter 42 is trapped in and around the swabshaped member 40. Additional embolic composition solidifies in shellsaround the core provided by the swab shaped member 40. Appropriatematerials for the swab shaped member 40 include biocompatible materials,such as polyester, PTFE, silk, Dacron, polyethylene, nylon,fluoropolymer, cotton, and the like. The shape and size of the swab 40may be modified to correspond with a particular shape and size of anembolization site.

A further embodiment of the liquid embolic delivery system, as shown inFIGS. 9 and 10, includes a node 50, such as an electrically chargedmember or a magnet, which attracts the liquid embolic compositiondelivered through the lumen of a catheter 52. The node 50 can be fixedon the end of the catheter 52 or preferably is movable from a retractedposition, shown in FIG. 9, to an extended position, shown in FIG. 10, bya rod 54 extending through the catheter lumen. The polymer preferablyincludes magnetic particles which are attracted to the node. The node 50is positioned generally in a center of an embolization site and theliquid embolic agent solidifies in shells around the node.

FIGS. 11-13 illustrate a method of treating an aneurysm with the liquidembolic delivery system having the wire nest 54 which has been describedabove with respect to FIGS. 3 and 4. As shown in FIG. 11, the catheter22 is positioned at or near a neck 60 of an aneurysm 62 and the wire 20is passed through the lumen of the catheter 22 to form a wire nest 24within the aneurysm. The liquid embolic material is then injectedthrough the lumen of the catheter 22 and is trapped by the wire nest 24during solidification. Injection of the liquid embolic materialcontinues until the aneurysm 62 is completely or substantially filledwith an embolic mass 64 as illustrated in FIG. 12. The catheter is thendetached from the solidified mass 64 of liquid embolic material withinthe aneurysm by chemical, mechanical, or electrical detachment means.For example, the mass 64 of embolic composition may be detached byholding the catheter 22 stationary while pulling the wire 20 proximallywithin the catheter lumen to break the wire at a location where the wireenters the liquid embolic mass. The catheter 22 and the wire 20 are thenremoved from the embolization site leaving the liquid embolic mass 64and the wire nest 24 embedded within the mass in the aneurysm. The wire20 which has been broken as described above may also be used as a pusherto separate the embolic mass 64 from the catheter 22. This method oftreating an aneurysm may also be used for other embolization treatments.

The liquid embolic delivery system according to the present inventionmay be configured so that injection of liquid embolic composition formsas consecutive shells over a beginning kernel as the embolic massincreases in size. Alternatively, the liquid embolic may be injectedfrom a center of the containment member so that an outer skin is createdfirst and additional embolic is added inside the mass causing the outerskin to expand.

FIGS. 14-16 illustrate a liquid embolic delivery system including aflexible sack 70 affixed to a distal end of a catheter 72. The edges 78of the flexible sack 70 are affixed in a known manner to an exterior ofthe catheter distal tip such that the flexible sack surrounds thecatheter outlet. The catheter 72 having the flexible sack 70 affixed tothe distal end are delivered to an embolization site through anintroducer catheter 76 having a somewhat larger diameter than thecatheter 72. Once the flexible sack 70 is placed within the embolizationsite such as within an aneurysm, a liquid embolic composition isinjected through the catheter lumen.

The flexible sack 70 is formed of a membrane or woven material which issubstantially impermeable to the precipitate of the liquid emboliccomposition while being permeable to the solvent to allow the solvent todissipate from the liquid embolic material injected into the flexiblesack. Examples of biocompatible materials which may be used to form theflexible sack 70 include polyester, PTFE, urethane, Dacron, nylon,polyethylene, fluoropolymers, silicone, and the like. According to oneembodiment, the flexible sack is a mesh bag having a structure whichallows the diameter of the bag to increase as the embolic composition isinjected. The mesh material may be non-elastic or may be elastic actinglike a balloon. The mesh allows the solvent to dissipate out of the bagwhile the structure of the bag prevents fingers or strands of embolicmaterial from passing out of the embolization area. The flexible sack 70is detachable from the distal end of the catheter 72 once theembolization is complete so that the catheter can be removed from theembolization site.

The method of detachment of any one of the containment members describedabove from the catheter of the present invention may be eithermechanical, electrical, or chemical. One example of a mechanical methodof detachment involves forcibly detaching the mass of embolic materialand the containment member from the distal tip of the catheter such asby use of a plunger member extending through the lumen of the catheter.Alternatively, an outer catheter sleeve may be used to strip a mass froma distal tip of the catheter. Mechanical detachment can also beperformed by various interlocking, pushing, twisting, and lockingmotions.

Electrical detachment may be performed by providing a weakened sectionat a junction between the containment member and the catheter which iseasily vaporized by application an electric current. For example, a 9Velectric power source may apply a current of about 0.3 mA fordetachment. One example of an electrical detachment mechanism isdescribed in U.S. Pat. No. 5,928,226, which is incorporated herein byreference.

Finally, with a chemical detachment mechanism, a dissolvable detachmentsection is included in the delivery system between the catheter and thecontainment member or at the distal end of the catheter. The dissolvabledetachment section is dissolved, softened, swollen, degraded, orotherwise changed by the injection of a biocompatible chemical throughthe catheter. Some examples of chemical detachment systems includedissolvable detachment sections, such as a polymer section which isdissolved by DMSO, a nylon section which is dissolved by a fluorinatedhydrocarbon, or sections which are dissolved by saline or any of theother biocompatible solvents discussed above.

FIGS. 17-20 illustrate a liquid embolic delivery system which disturbsthe blood flow into and out of the aneurysm to improve control overinjection of the liquid embolic composition. The disturbance of bloodflow into and out of the aneurysm through the aneurysm neck creates alow turbulence or “peaceful” fluid environment within the aneurysm whichallows improved filling of the aneurysm with the embolic material.

As shown on FIG. 17, a delivery system 100 is placed at an embolizationsite such as an aneurysm 90 having an aneurysm neck 92. The deliverysystem has two lumens including an inner lumen 102 for delivery of theliquid embolic composition and an outer lumen 104 for injection of afluid such as saline which is used to disrupt blood flow at the aneurysmneck 92. The delivery system 100 may be formed from an inner catheter106 and an outer catheter 108 concentrically surrounding the innercatheter and having a plurality of side ports 110 which can bepositioned at the aneurysm neck 92. A distal end of the outer catheter108 forms a fluid tight seal with an exterior of the inner catheter 106.This distal end of the outer catheter 108 may be permanently bonded tothe inner catheter or may be slideable over the inner catheter with orwithout a valve member. The inner and outer catheters 106, 108 may beprovided with radiopaque markers 112 for visualization of the positionof the inner and outer catheters. Alternatively, a radiopaque marker maybe sandwiched between the two tubes at a fuse joint at the distal end ofthe outer catheter 108.

The side holes 110 are preferably spaced around the outer catheter 108and are positioned within an area of a relatively short axial length. Inuse, the delivery system 100 is guided to an aneurysm over a guidewireusing the inner catheter lumen 102 as a guidewire lumen. The tip of theinner lumen is located within the dome of the aneurysm and the sideholes 110 are positioned near the aneurysm neck 92. The guidewire isthen removed and the disruption fluid is then injected through the outercatheter 108 and exits the side holes 110 of the delivery device. Thedisruption fluid can be any biocompatible fluid such as saline, contrastmedium, or mixtures thereof. The flow of the disruption fluid isvisualized and adjusted so that optimum disruption of blood flow at theaneurysm neck occurs. The liquid embolic material is then injectedthrough the lumen 102 of the center catheter 106 until the aneurysm 90has been filled and the embolic composition is solidified.

According to one embodiment of the present invention, the inner catheter106 is slideable with respect to the outer catheter 108 to allowadjustment of the distance between the distal tip where the liquidembolic composition is injected and the disruption side holes 110. Theability to adjust the delivery device 100 in this manner is usefulbecause aneurysm vary in size. A valve at the distal end of the outercatheter 108 can allow the outer catheter to slide easily over the innercatheter in an axial direction without the leakage of fluid.

FIGS. 18-20 illustrate an alternative embodiment of a delivery system120 which allows a pattern of the disruption flow to be controlled.Because the necks 92 of many aneurysms 90 have non-circular orelliptical cross sections, it may be desirable to vary the flow rate ofthe aneurysm neck disrupting fluid out of different side holes aroundthe circumference of the delivery system. In other words, it may bedesirable to increase the disruption fluid flow at side holes which areoriented in a direction of a major axis of the elliptical neck whiledecreasing the flow at side holes which are oriented in the direction ofthe minor axis of the elliptical neck.

FIG. 18 illustrates an aneurysm 90 having an elliptical aneurysm neck 92and a delivery system 120 for delivery of liquid embolic composition anddisruption fluid to the aneurysm. The delivery system 120 includes anelongated catheter 122 with a central lumen 124 and a plurality ofsurrounding lumens 126. The surrounding lumens 126 are spaced around thecentral lumen 124 and each include a side port 128 for delivery of thedisruption fluid. FIG. 19 shows a cross section of the catheter 122taken along line A-A illustrating the central lumen 124 and a pluralityof surrounding lumens 126.

At a proximal end of the catheter 122 a fluid connection 130 is providedfor connection of the central lumen to a source of the liquid emboliccomposition. A fluid connection 132 is also provided for connection ofthe plurality of surrounding lumens 126 to a source of disruption fluid.A manifold 134 and a plurality of valves are provided for controllingdelivery of the disruption to the different surrounding lumens 126 atrelatively variable velocities. The manifold 134 and valves provide aflow regulating means for delivery of the fluid which allows the fluiddelivered from the different side ports 128 at the aneurysm neck 92 tobe carefully controlled as illustrated in FIG. 20.

According to a further embodiment of the liquid delivery having aneurysmneck disruption side flow, one or more rows of side holes may beprovided. These rows of side holes may be positioned just inside andjust outside the aneurysm neck to further disrupt the blood flow throughthe neck.

While the invention has been described in detail with reference to thepreferred embodiments thereof, it will be apparent to one skilled in theart that various changes and modifications can be made and equivalentsemployed, without departing from the present invention.

1. A liquid embolic delivery system comprising: a catheter having alumen for delivery of a liquid embolic composition to a cavity; acontainment member positioned at a distal end of the catheter, thecontainment member shaped to trap the liquid embolic compositiondelivered through the lumen of the catheter; and a detachment mechanismfor completely detaching the containment member from the catheter aftersolidification of the liquid embolic composition to allow separation ofthe catheter from a mass of solidified embolic composition.
 2. Theliquid embolic delivery system according to claim 1, wherein thecontainment member is a flexible sack which fills with the liquidembolic composition.
 3. The liquid embolic delivery system according toclaim 2, wherein the flexible sack is positioned over a distal outlet ofthe lumen with a neck of the sack connected to the distal end of thecatheter around an opening of the catheter lumen, the detachmentmechanism detaching the flexible sack neck from the distal end of thecatheter.
 4. The liquid embolic delivery system according to claim 2,wherein the flexible sack is formed of a mesh material which allowssolvent to pass through the sack, the mesh material containing theliquid embolic composition which has solidified.
 5. The liquid embolicdelivery system according to claim 2, wherein the flexible sack isformed as a resilient balloon over the distal end of the catheter. 6.The liquid embolic delivery system according to claim 1, wherein thecontainment member is a nidus extending from the distal end of thecatheter and positioned to trap the liquid embolic composition as theliquid embolic composition solidifies.
 7. The liquid embolic deliverysystem according to claim 6, wherein the nidus is formed from a wirewhich is delivered through the catheter lumen and forms a coil uponexiting the distal end of the lumen.
 8. The liquid embolic deliverysystem according to claim 6, wherein the nidus is in the form of a wirebrush.
 9. The liquid embolic delivery system according to claim 6,wherein the nidus is in the form of a swab.
 10. The liquid embolicdelivery system according to claim 6, wherein the nidus is in the formof a sponge.
 11. The liquid embolic delivery system according to claim6, wherein the nidus is in the form of a flexible sack.
 12. The liquidembolic delivery system according to claim 6, wherein the nidus isformed from a wire which is delivered through the catheter lumen andforms a randomly shaped nest upon exiting the distal end of the lumen.13. The liquid embolic delivery system according to claim 1, wherein thedetachment mechanism includes means for delivering an electrical chargeto a point between the containment member and the catheter to detach thecontainment member from the catheter.
 14. The liquid embolic deliverysystem according to claim 1, wherein the detachment mechanism includes achemical detachment section between the containment member and thecatheter which is dissolved by a chemical agent.
 15. A method ofcontaining a liquid embolic composition at an embolization site within abody comprising: delivering a liquid embolic composition to anembolization site within a body with a catheter; containing the liquidembolic composition during solidification with a containment member; anddetaching the containment member from the catheter after solidificationof the liquid embolic composition to release the catheter from a mass ofsolidified embolic composition.
 16. The method according to claim 15,wherein the liquid embolic composition is contained by trapping emboliccomposition in a nidus during solidification.
 17. The method accordingto claim 15, wherein the liquid embolic composition is contained by aflexible sack and solvent dissipates through the sack duringsolidification of the liquid embolic composition.
 18. The methodaccording to claim 15, wherein the containment member is positioned atthe embolization site before delivery of the liquid embolic compositionby moving the containment member out of a lumen of the catheter.
 19. Themethod according to claim 15, wherein the containment member and thecatheter are delivered to the embolization site through an introducingcatheter.
 20. A liquid embolic delivery system comprising: a catheterhaving a distal end, a proximal end, and a lumen for delivery of aliquid embolic composition to a cavity wherein said distal end isdetachable; and a detachment means for detaching the distal end of thecatheter after solidification of the liquid embolic composition.
 21. Theliquid embolic delivery system of claim 20, wherein said liquid emboliccomposition comprises a biocompatible polymer combined with abiocompatible solvent.
 22. The liquid embolic delivery system of claim21, wherein said polymer is ethylene vinyl alcohol copolymer and thesolvent is dimethyl sulfoxide (DMSO).
 23. The liquid embolic deliverysystem of claim 20, wherein said detachment means is a chemical,mechanical, or electrical detachment means.
 24. A method of delivering aliquid embolic composition at an embolization site within a bodycomprising: delivering a liquid embolic composition to an embolizationsite within a body with a catheter having a distal end and a proximalend; and detaching the distal end of the catheter after solidificationof the liquid embolic composition to release the catheter from a mass ofsolidified embolic composition.
 25. The method of claim 24, furthercomprising removing the proximal end of the catheter from the body.